Corrosion resistant alloy



UNITED STATES PATENT OFFICE CORROSION RESISTANT ALLOY Carl Carius,Essen-Rellinghausen, Germany,

Krupp Aktiengeselischaft,

signor to Fried.

Essen-on-th'e-Ruhr, Germany No Drawing. Application September 10, 1936,Serial No. 100,115. In Germany December 19,

2 Claims. (Cl. 75-125) My invention relates to corrosion-resistantchromium-nickel-molybdenum-iron alloys having an addition of antimony.These alloys are remarkable for very high resistance to corrosion.

6 For example, their resistance to caustic soda solution or causticpotash solution and especially to hydrochloric acid is far superior tothat of the usual chromium-nickel-molybdenum-iron alloys, for example ofthe known austenitic chromiumnickel-molybdenum steels. The new alloysmay be further improved by an addition of copper.

In my co-pending application for Letters Patent, Serial Number 28,943,filed June 28, 1935,

15 which matured into Patent No. 2,054,927 on Sept. 22, 1936, I havealready suggested alloys of the following composition:

I have now found that the above-mentioned high resistance to corrosionof these alloys is also obtained already with antimony contents of 300.5 to 2.%. So, for example, an alloy containing Percent Carbon 0.04Chrom 13. Nickel 30.

Percent Molybdenum 5. Copper 5. Antimony 1.5

Balance iron with the usual impurities has been tested in 25.%hydrochloric acid solution at a temperature of 80 centigrade. The lossin weight occurring by this treatment amounted only to from 1 to 2grammes per sq. meter per hour.

Preferably I use alloys of the following composition:

Percent Carbon 0.02- 0.2. Chromium 10. 20. Nickel 2'7. -33. Molybdenum2. 5. Copper- 2. 6. Antimony l0.5 2.

Balance iron with or without the normal impurities.

